WO2022161179A1

WO2022161179A1 - Preparation method for reprocessable thermosetting polyester amide, and prepared thermosetting polyester amide

Info

Publication number: WO2022161179A1
Application number: PCT/CN2022/071753
Authority: WO
Inventors: 汪钟凯; 丁永良; 刘成
Original assignee: 安徽农业大学
Priority date: 2021-01-26
Filing date: 2022-01-13
Publication date: 2022-08-04
Also published as: US20220363828A1; CN112920403A; CN112920403B

Abstract

The present invention relates to the technical field of polyester amide resins, and disclosed is a preparation method for a reprocessable thermosetting polyester amide. The present invention comprises the following steps: (1) heating and dissolving 30-200 parts by weight of a liquid dicarboxylic acid and 15-95 parts by weight of a diamine compound containing β-hydroxyl to form a reaction liquid; (2) adding 0.05-0.5 parts by weight of a catalyst, heating same to 65-100°C in a nitrogen atmosphere and reacting same for 1-6 h; (3) heating the reaction liquid to 100-180°C, and reacting same for 3-18 h; (4) reheating the reaction system of the reaction liquid to 180-240°C, and reacting same for 0.5-4 h; and (5) cooling the reaction system of the reaction liquid to 100-180°C. Further provided is a polyester amide prepared by means of the preparation method. The present invention has the beneficial effect of an amido bond, ester bond and hydroxyl in the polyester amide of the present invention being simultaneously present, such that the polyester amide can be repeatedly processed while having high heat resistance.

Description

Preparation method of reworkable thermosetting polyester amide, obtained thermosetting polyester amide

technical field

The invention relates to the technical field of polyester amide resins, in particular to a preparation method of a reprocessable thermosetting polyester amide and the prepared thermosetting polyester amide.

Background technique

Common synthetic polymer resins in life can be divided into thermosetting resins and thermoplastic resins. As the name implies, after the thermoplastic resin is heated to a certain temperature, its intermolecular force is destroyed due to the temperature to make it fluid. For example, the common molecular chain entanglement, van der Waals force and hydrogen bond will weaken or disappear, so thermoplastic resin Reworkable. However, for thermosetting resins. Because it is limited by the cross-linked network of covalent bonds, the material itself does not have reprocessability. Therefore, thermosetting materials endow materials with better thermal stability. For example, common plug-in boards, switch panels, etc. are made of thermosetting resins.

Thermosetting resins have good dimensional stability and are widely used in all aspects of life, but it cannot be ignored that the non-recyclable thermosetting materials cause environmental pollution and waste of resources. Although many reworkable thermosetting resins have been developed in recent years, which have reworkable properties by introducing dynamic covalent bonds into the materials, bio-based thermosetting materials are still rarely reported. For example, the patent with publication number CN110903463A discloses a vegetable oil-based reprocessable thermosetting shape memory epoxy resin and a preparation method thereof. The sample is cut into pieces, and a certain pressure is given to it at a high temperature of 130-200 ° C, so that the sample material reaches a dynamic state. Under transesterification conditions, the topology of the crosslinked network rearranges and can be reworked into new shapes.

As we all know, dimer acid refers to the self-polycondensation of linear unsaturated fatty acid or unsaturated fatty acid ester with linoleic acid of natural oil as the main component under the catalysis of clay, through Diels-Alder cycloaddition reaction and other self-condensation. aggregates. The dimer acid remains in a liquid state at room temperature due to the presence of long side chains in its structure. At present, dimer acid is mainly used in coatings, surfactants, lubricants, printing inks, hot melt adhesives, etc. Through its application, it can be found that it has not been used in resins, and the reason for this is that dimer acid itself is composed of dimers, small amounts of trimers or multimers, and trace amounts of unreacted monomers. Various compounds Therefore, it is difficult to directly prepare high-performance polyamides by polycondensation with diamine monomers in equal proportions. In addition, although dimer acids and polyamines have been reported to react to form curing agents, they are still far away from high-performance plastics.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is that the polyamide synthesized by using dimer acid in the prior art has poor performance.

The invention solves the above technical problems through the following technical means:

The invention provides a preparation method of a reprocessable thermosetting polyester amide, comprising the following steps:

(1) heating and dissolving 30-200 parts by weight of a liquid dicarboxylic acid and 15-95 parts by weight of a diamine compound containing a beta hydroxyl group and stirring to form a reaction solution;

(2) adding 0.05-0.5 parts by weight of catalyst to the reaction solution, heating to 65-100° C. under nitrogen atmosphere for 1-6 hours;

(3) heating the reaction solution in step 2 to 100～180℃ for 3～18h;

(4) subjecting the reaction solution in step 3 to reacting the reaction system at 180-240° C. for 0.5-4 h;

(5) cooling the reaction system of the reaction solution in step 4 to 100-180° C. to obtain a reprocessable thermosetting polyester amide.

Beneficial effects: the amide bond, ester bond and hydroxyl group coexist in the polyester amide prepared by the present invention, so that the polyester amide can be processed repeatedly while having high heat resistance, and the reaction monomer is not affected by the purity of the monomer, Therefore, the liquid dicarboxylic acid has a wider application prospect in the reprocessable thermosetting resin. The breaking strength of the prepared polyester amide is 1-100 MPa, and the breaking elongation is 1-500%.

The liquid dicarboxylic acid used can meet the requirements that the reaction system is still in a molten state at low temperature at the initial stage, and the reaction can be carried out smoothly at low temperature, so that the amino group can react as much as possible in the initial stage of the reaction, so as to achieve the end point of the reaction and still have hydroxyl groups The presence.

The polyester amide in the present invention is synthesized from a dimer acid compound and a diamine compound containing a beta hydroxyl group without adding a solvent, the synthesis method is simple, the environment is not polluted, the product does not need to be purified and removed, and the recovery is simple.

The monomer dimer acid synthesized by the polyester amide in the present invention is not affected by the purity, and can be monofunctional or multifunctional, and the mechanical strength of the polyester amide can be controlled by controlling the feeding ratio of the liquid dicarboxylic acid.

The introduction of nitrogen gas in the preparation process of the present invention can prevent the material from being oxidized at high temperature, and at the same time blow out the generated small molecules, so as to promote the forward reaction of the reaction.

Multi-step heating involves the degree of reaction. The selection of reaction conditions is based on long-term exploration of experiments. The reaction conditions are controlled, and the low temperature time is extended as much as possible to increase the reaction ratio of amino groups, so that the activity of amino groups is higher than that of hydroxyl groups. Therefore, hydroxyl groups are not easy to react at low temperature. The purpose of maintaining the temperature at 100-180°C for a long time is that the amino groups in the monomers can react as much as possible, so as to achieve that the hydroxyl groups are still retained at the end of the reaction, so that the resulting polymer still has the ability to be reprocessed. The multi-step heating and cooling is to take out at a low temperature and prevent it from being oxidized by air.

If the reaction ratio or conditions are not within the recorded range, the impact on the product is poor mechanical properties, but it still has the ability to be reprocessed. This is because the monomer feed that is not within the conditions will make the polymer more small molecules, so it will lead to mechanical properties. worse.

Preferably, the ratio of the molar amount of the carboxylic acid in the liquid dicarboxylic acid to the molar amount of the amino group in the β-hydroxyl-containing diamine compound is 0.5-1.5:1.

Beneficial effect: The selection of the weight parts of each raw material is calculated according to the molar ratio of the monomers used. Different molar ratios have different mechanical properties. Therefore, the molar ratio of the raw materials is adjusted by adjusting the weight parts of each raw material to ensure the liquid dibasic carboxylic acid. The feeding of the carboxyl group in the acid is greater than or equal to the feeding of the amino group in the diamine.

Preferably, the structural formula of the liquid dicarboxylic acid compound is

The structural formula of the β-hydroxyl-containing diamine compound is

Preferably, the catalyst includes any one of sodium phosphite, sodium hypophosphite and zinc acetate.

Preferably, the liquid dicarboxylic acid comprises tall oil dimer acid.

Preferably, the liquid dicarboxylic acid includes one or more of the following structural formulas:

Preferably, the diamine compound containing beta hydroxyl group is 1,3 diamino-2-propanol.

Preferably, the preparation method of the reworkable thermosetting polyester amide comprises the following steps:

(1) 41.6g tall oil dimer acid and 6.8g 1,3 diamino-2-propanol are heated and dissolved and stirred to form a reaction solution;

(2) adding 80 mg of sodium phosphite to the reaction solution, heating at 80° C. for 1 h under nitrogen atmosphere;

(3) heating the reaction solution in step (2) to 140°C for 12h, and then heating to 180°C for 6h;

(4) react the reaction system of the reaction solution in step (3) to 230°C for 2h;

(5) cooling the reaction system of the reaction solution in step (4) to 140° C. to obtain a reprocessable thermosetting polyester amide.

(1) 38.4g tall oil dimer acid and 6.8g 1,3 diamino-2-propanol are heated and dissolved and stirred to form a reaction solution;

(1) 35.2g tall oil dimer acid and 6.8g 1,3 diamino-2-propanol are heated and dissolved and stirred to form a reaction solution;

(1) 44.8g tall oil dimer acid and 6.8g 1,3 diamino-2-propanol are heated and dissolved and stirred to form a reaction solution;

(1) 32g tall oil dimer acid and 6.8g 1,3 diamino-2-propanol are heated and dissolved and stirred to form a reaction solution;

The present invention also provides the thermosetting polyester amide prepared by the above preparation method.

Beneficial effects: the amide bond, ester bond and hydroxyl group exist simultaneously in the thermosetting polyester amide prepared by the invention, so that the polyester amide can be processed repeatedly while having high heat resistance.

In the present invention, the breaking strength of the polyester amide is 1-100 MPa, and the breaking elongation is 1-500%.

The advantages of the present invention lie in that amide bonds, ester bonds and hydroxyl groups coexist in the polyester amide prepared by the invention, so that the polyester amide can be processed repeatedly while having high heat resistance, and the reaction monomer is not affected by the purity of the monomer. Therefore, liquid dicarboxylic acids have wider application prospects in reprocessable thermosetting resins. The breaking strength of the prepared polyester amide is 1-100 MPa, and the breaking elongation is 1-500%.

Description of drawings

FIG. 1 is a schematic diagram of the reaction structure of tall oil dimer acid in the embodiment of the present invention.

Fig. 2 is the infrared spectrogram of polyester amide in Example 1 of the present invention.

FIG. 3 is the stress-strain curves of polyester amides in Example 1-Example 2 of the present invention.

Fig. 4 is the glass transition temperature change of polyester amide in Example 1-Example 5 of the present invention.

5 is a comparison of infrared spectra of polyester amide repeated tableting in Example 1 of the present invention.

FIG. 6 is a comparison photo of polyester amide before and after repeated tableting in Example 1 of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are part of the present invention. examples, but not all examples. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The test materials and reagents used in the following examples can be obtained from commercial sources unless otherwise specified.

If the specific technology or condition is not indicated in the embodiment, it can be carried out according to the technology or condition described in the literature in this field or according to the product specification.

In the following examples, tall oil dimer acid was provided by Medvisvaco (China) Investment Co., Ltd.

Example 1

The preparation of polyester amide specifically includes the following steps:

Take 32 g of tall oil dimer acid, 6.8 g of 1,3-diamino-2-propanol, and 80 mg of sodium phosphite into a three-necked flask, mix them uniformly with a mechanical stirrer under a nitrogen atmosphere at 80 °C, and heat them for 1 hour, then heat up to 140 °C for the reaction. 12h, then the temperature was raised to 180°C for 6h, then the temperature was raised to 230°C for 2h, and finally the reaction system was cooled to 140°C. After the reaction, the product was taken out and stored in a sealed container, and the product was named polyesteramide 1.

As shown in Figure 1: after the raw material tall oil dimer acid of the present invention reacts according to Example 1, the carboxyl peak basically disappears, and the peaks of the amide group and the ester group are newly generated, which means that the reaction is successful, and the amine group is basically converted into an amide group. . At the same time, due to the existence of hydroxyl group, it reacts with carboxyl group to generate ester group, that is, polyester amide is successfully prepared in the present invention.

Tall oil dimer acid is a bifunctional mixture. By polycondensing it with a trifunctional monomer containing β-hydroxyl, the activity of the amino group is higher than that of the hydroxyl group, and the reaction time at low temperature is fully extended, so that the amino group is fully used. There may be many reactions, and then cross-linking at high temperature is that the unreacted carboxyl group reacts with the hydroxyl group. Because the material is fed according to the molar ratio during feeding, the number of carboxyl groups is always less than the sum of the hydroxyl group and the amino group, so the end point of the reaction passes through the infrared ray at 3300. The hydroxyl peak shows that there are still hydroxyl groups. In addition, according to the transesterification reaction mechanism, the cross-linked polymer can be reprocessed.

Example 2

The preparation of polyester amide specifically includes the following steps:

Take 35.2 g of tall oil dimer acid, 6.8 g of 1,3-diamino-2-propanol, and 80 mg of sodium phosphite into a three-necked flask, mix them uniformly with a mechanical stirrer under a nitrogen atmosphere at 80 °C, and heat for 1 hour, then heat up to 140 °C The reaction was carried out for 12 h, then heated to 180 °C for 6 h, then heated to 230 °C for 2 h, and finally the reaction system was cooled to 140 °C.

Example 3

The preparation of polyester amide specifically includes the following steps:

Take 38.4 g of tall oil dimer acid, 6.8 g of 1,3-diamino-2-propanol, and 80 mg of sodium phosphite into a three-necked flask, mix them uniformly with a mechanical stirrer under a nitrogen atmosphere at 80 °C, and heat for 1 hour, then heat up to 140 °C The reaction was carried out for 12 h, then heated to 180 °C for 6 h, then heated to 230 °C for 2 h, and finally the reaction system was cooled to 140 °C.

Example 4

The preparation of polyester amide specifically includes the following steps:

Take 41.6 g of tall oil dimer acid, 6.8 g of 1,3-diamino-2-propanol, and 80 mg of sodium phosphite into a three-necked flask, mix them uniformly with a mechanical stirrer under a nitrogen atmosphere at 80 °C, and heat for 1 hour, then heat up to 140 °C The reaction was carried out for 12 h, then heated to 180 °C for 6 h, then heated to 230 °C for 2 h, and finally the reaction system was cooled to 140 °C.

Example 5

The preparation of polyester amide specifically includes the following steps:

Take 44.8 g of tall oil dimer acid, 6.8 g of 1,3-diamino-2-propanol, and 80 mg of sodium phosphite into a three-necked flask, mix them uniformly with a mechanical stirrer under a nitrogen atmosphere at 80 °C, and heat for 1 hour, then heat up to 140 °C The reaction was carried out for 12 h, then heated to 180 °C for 6 h, then heated to 230 °C for 2 h, and finally the reaction system was cooled to 140 °C.

Tall oil dimer acid is a multi-component mixture, and Figure 2 is a conceptual diagram of the reaction of tall oil dimer acid.

As shown in Figure 3, polyester amides 1, 2, 3, 4 and 5 were prepared. It can be found that under the condition of constant 1,3 diamino-2-propanol content, with the increase of tall oil dimer acid content As the material increases, the mechanical properties of the material gradually transition from plastic to elastomer. The tensile properties of the splines are tested according to GB/T 1040.3-2006, the tensile rate is 10mm/min, and the test is performed under constant temperature and humidity conditions.

As shown in Figure 4, polyester amides 1, 2, 3, 4 and 5 were prepared. It can be found that under the condition of constant 1,3 diamino-2-propanol content, with the increase of tall oil dimer acid content As the temperature increases, the glass transition temperature of the material gradually decreases.

As shown in Figure 5, after the polyester amide 1 was repeatedly pressed, the infrared display group did not change, indicating that it could be processed repeatedly.

As shown in Fig. 6, the polyester amide 1 can still be tableted after being cut into pieces after tableting.

The above embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: The recorded technical solutions are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

A kind of preparation method of reprocessable thermosetting polyester amide, is characterized in that: comprises the following steps:

(1) heating and dissolving 30-200 parts by weight of a liquid dicarboxylic acid and 15-95 parts by weight of a diamine compound containing a beta hydroxyl group and stirring to form a reaction solution;

(2) adding 0.05-0.5 parts by weight of catalyst to the reaction solution, heating at 65-100° C. for 1-6 hours under nitrogen atmosphere;

(3) heating the reaction solution in step 2 to 100～180°C for 3～18h;

(4) subjecting the reaction solution in step 3 to reacting the reaction system at 180-240° C. for 0.5-4 h;

(5) cooling the reaction system of the reaction solution in step 4 to 100-180° C. to obtain a reprocessable thermosetting polyester amide.
The method for preparing a reprocessable thermosetting polyester amide according to claim 1, wherein the structural formula of the liquid dicarboxylic acid compound is:
The structural formula of the β-hydroxyl-containing diamine compound is
[Correction 25.01.2022 under Rule 91]
The method for preparing a reworkable thermosetting polyester amide according to claim 1, wherein the catalyst comprises any one of sodium phosphite, sodium hypophosphite and zinc acetate.
[Correction 25.01.2022 under Rule 91]
The preparation method of the reprocessable thermosetting polyester amide according to claim 1, wherein the liquid dicarboxylic acid comprises one or more of the following structural formulas:
[Correction 25.01.2022 under Rule 91]
The method for preparing a reprocessable thermosetting polyester amide according to claim 1, wherein the diamine compound containing β hydroxyl group is 1,3 diamino-2-propanol.
[Correction 25.01.2022 under Rule 91]
The method for preparing a reworkable thermosetting polyester amide according to claim 1, wherein the dimer acid comprises tall oil dimer acid.
[Correction 25.01.2022 under Rule 91]

The preparation method of reprocessable thermosetting polyester amide according to claim 4, is characterized in that: comprises the following steps:

(1) 41.6g tall oil dimer acid and 6.8g 1,3 diamino-2-propanol are heated and dissolved and stirred to form a reaction solution;

(2) adding 80 mg of sodium phosphite to the reaction solution, heating at 80° C. for 1 h under nitrogen atmosphere;

(3) heating the reaction solution in step 2 to 140°C for 12h, and then heating to 180°C for 6h;

(4) react the reaction system of the reaction solution in step 3 to 230°C for 2h;

(5) cooling the reaction system of the reaction solution in step 4 to 140° C. to obtain a reprocessable thermosetting polyester amide.
[Correction 25.01.2022 under Rule 91]

The preparation method of reprocessable thermosetting polyester amide according to claim 4, is characterized in that: comprises the following steps:

(1) 38.4g tall oil dimer acid and 6.8g 1,3 diamino-2-propanol are heated and dissolved and stirred to form a reaction solution;

(2) adding 80 mg of sodium phosphite to the reaction solution, heating at 80° C. for 1 h under nitrogen atmosphere;

(3) heating the reaction solution in step (2) to 140°C for 12h, and then heating to 180°C for 6h;

(4) react the reaction system of the reaction solution in step (3) to 230°C for 2h;

(5) cooling the reaction system of the reaction solution in step (4) to 140° C. to obtain a reprocessable thermosetting polyester amide.
[Correction 25.01.2022 under Rule 91]

The preparation method of reprocessable thermosetting polyester amide according to claim 4, is characterized in that: comprises the following steps:

(1) 35.2g tall oil dimer acid and 6.8g 1,3 diamino-2-propanol are heated and dissolved and stirred to form a reaction solution;

(2) adding 80 mg of sodium phosphite to the reaction solution, heating at 80° C. for 1 h under nitrogen atmosphere;

(3) heating the reaction solution in step (2) to 140°C for 12h, and then heating to 180°C for 6h;

(4) react the reaction system of the reaction solution in step (3) to 230°C for 2h;

(5) cooling the reaction system of the reaction solution in step (4) to 140° C. to obtain a reprocessable thermosetting polyester amide.
[Correction 25.01.2022 under Rule 91]

The preparation method of reprocessable thermosetting polyester amide according to claim 4, is characterized in that: comprises the following steps:

(1) 44.8g tall oil dimer acid and 6.8g 1,3 diamino-2-propanol are heated and dissolved and stirred to form a reaction solution;

(2) adding 80 mg of sodium phosphite to the reaction solution, heating at 80° C. for 1 h under nitrogen atmosphere;

(3) heating the reaction solution in step (2) to 140°C for 12h, and then heating to 180°C for 6h;

(4) react the reaction system of the reaction solution in step (3) to 230°C for 2h;

(5) cooling the reaction system of the reaction solution in step (4) to 140° C. to obtain a reprocessable thermosetting polyester amide.
[Correction 25.01.2022 under Rule 91]
A reprocessable thermosetting polyester amide prepared by the preparation method according to any one of claims 1-9.